The perichondrium supplies blood to the auricular cartilage. Blunt trauma to the pinna may cause a subperichondrial hematoma; the accumulation of large amounts of blood between the perichondrium and cartilage can interrupt the blood supply to the cartilage and render all or part of the pinna a shapeless, reddish purple mass. Avascular necrosis of the cartilage may follow. The resultant destruction causes the characteristic cauliflower ear of wrestlers and boxers.
Treatment consists of promptly evacuating the clot through an incision and preventing reaccumulation of the hematoma with through-and-through ear sutures over dental gauze rolls or insertion of a Penrose drain plus a pressure dressing. Because these injuries are prone to infection and abscess formation, an oral antibiotic effective against staphylococci (eg, cephalexin 500 mg 3 times a day) is given for 5 days.
In lacerations of the pinna, the skin margins are sutured whenever possible. If the cartilage is penetrated, it is repaired unless there is not enough skin to cover it. Damaged cartilage, whether repaired or not, is splinted externally with benzoin-impregnated cotton, and a protective dressing is applied. Oral antibiotics are given as for a hematoma.
Human bite wounds are at high risk of infection, including infection of the cartilage, a potentially severe complication. Treatment includes meticulous debridement of devitalized tissue, prophylactic antibiotics (eg, amoxicillin/clavulanate 500 to 875 mg orally 2 times a day for 3 days), and possibly antivirals (see table Antimicrobials for Bite Wounds). Wounds < 12 hours old can be closed but older wounds should be allowed to heal secondarily, with cosmetic deformities treated later.